lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame^] | 1 | /* Thread-local storage handling in the ELF dynamic linker. s390 version. |
| 2 | Copyright (C) 2003-2015 Free Software Foundation, Inc. |
| 3 | This file is part of the GNU C Library. |
| 4 | |
| 5 | The GNU C Library is free software; you can redistribute it and/or |
| 6 | modify it under the terms of the GNU Lesser General Public |
| 7 | License as published by the Free Software Foundation; either |
| 8 | version 2.1 of the License, or (at your option) any later version. |
| 9 | |
| 10 | The GNU C Library is distributed in the hope that it will be useful, |
| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | Lesser General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU Lesser General Public |
| 16 | License along with the GNU C Library; if not, see |
| 17 | <http://www.gnu.org/licenses/>. */ |
| 18 | |
| 19 | |
| 20 | /* Type used for the representation of TLS information in the GOT. */ |
| 21 | typedef struct |
| 22 | { |
| 23 | unsigned long int ti_module; |
| 24 | unsigned long int ti_offset; |
| 25 | } tls_index; |
| 26 | |
| 27 | |
| 28 | #ifdef SHARED |
| 29 | |
| 30 | extern unsigned long __tls_get_offset (unsigned long got_offset); |
| 31 | |
| 32 | # if IS_IN (rtld) |
| 33 | |
| 34 | # include <shlib-compat.h> |
| 35 | |
| 36 | /* dl-tls.c declares __tls_get_addr as an exported symbol if it is not defined |
| 37 | as a macro. It seems suitable to do that in the generic code because all |
| 38 | architectures other than s390 export __tls_get_addr. The declaration causes |
| 39 | problems in s390 though, so we define __tls_get_addr here to avoid declaring |
| 40 | __tls_get_addr again. */ |
| 41 | # define __tls_get_addr __tls_get_addr |
| 42 | |
| 43 | extern void *__tls_get_addr (tls_index *ti) attribute_hidden; |
| 44 | /* Make a temporary alias of __tls_get_addr to remove the hidden |
| 45 | attribute. Then export __tls_get_addr as __tls_get_addr_internal |
| 46 | for use from libc. We do not want to export __tls_get_addr, but we |
| 47 | do need to use it from libc when looking up the address of a TLS |
| 48 | variable. We don't use __tls_get_offset because it requires r12 to |
| 49 | be setup and that might not always be true. Either way it's more |
| 50 | optimal to use __tls_get_addr directly (that's what |
| 51 | __tls_get_offset does anyways). */ |
| 52 | strong_alias (__tls_get_addr, __tls_get_addr_internal_tmp); |
| 53 | versioned_symbol (ld, __tls_get_addr_internal_tmp, |
| 54 | __tls_get_addr_internal, GLIBC_PRIVATE); |
| 55 | |
| 56 | /* The special thing about the s390 TLS ABI is that we do not have the |
| 57 | standard __tls_get_addr function but the __tls_get_offset function |
| 58 | which differs in two important aspects: |
| 59 | 1) __tls_get_offset gets a got offset instead of a pointer to the |
| 60 | tls_index structure |
| 61 | 2) __tls_get_offset returns the offset of the requested variable to |
| 62 | the thread descriptor instead of a pointer to the variable. |
| 63 | */ |
| 64 | # ifdef __s390x__ |
| 65 | asm("\n\ |
| 66 | .text\n\ |
| 67 | .globl __tls_get_offset\n\ |
| 68 | .type __tls_get_offset, @function\n\ |
| 69 | .align 4\n\ |
| 70 | __tls_get_offset:\n\ |
| 71 | la %r2,0(%r2,%r12)\n\ |
| 72 | jg __tls_get_addr\n\ |
| 73 | "); |
| 74 | # elif defined __s390__ |
| 75 | asm("\n\ |
| 76 | .text\n\ |
| 77 | .globl __tls_get_offset\n\ |
| 78 | .type __tls_get_offset, @function\n\ |
| 79 | .align 4\n\ |
| 80 | __tls_get_offset:\n\ |
| 81 | basr %r3,0\n\ |
| 82 | 0: la %r2,0(%r2,%r12)\n\ |
| 83 | l %r4,1f-0b(%r3)\n\ |
| 84 | b 0(%r4,%r3)\n\ |
| 85 | 1: .long __tls_get_addr - 0b\n\ |
| 86 | "); |
| 87 | # endif |
| 88 | # else /* IS_IN (rtld) */ |
| 89 | extern void *__tls_get_addr_internal (tls_index *ti); |
| 90 | # endif /* !IS_IN (rtld) */ |
| 91 | |
| 92 | # define GET_ADDR_OFFSET \ |
| 93 | (ti->ti_offset - (unsigned long) __builtin_thread_pointer ()) |
| 94 | |
| 95 | /* Use the privately exported __tls_get_addr_internal instead of |
| 96 | __tls_get_offset in order to avoid the __tls_get_offset special |
| 97 | linkage requiring the GOT pointer to be set up in r12. The |
| 98 | compiler will take care of setting up r12 only if itself issued the |
| 99 | __tls_get_offset call. */ |
| 100 | # define __TLS_GET_ADDR(__ti) \ |
| 101 | ({ __tls_get_addr_internal (__ti) \ |
| 102 | + (unsigned long) __builtin_thread_pointer (); }) |
| 103 | |
| 104 | #endif |
| 105 | |
| 106 | /* Value used for dtv entries for which the allocation is delayed. */ |
| 107 | #define TLS_DTV_UNALLOCATED ((void *) -1l) |